Slidewire contact mechanism



@ch 3, 1967 G. EHRENBERG ETAL. 3,345,492

SLIDEWIRE CONTACT MECHANI SM Filed Sept. 28, 1966 M/VE/VTORS.

GUST/3V5 EHRENBERG FRANK J. MCULLA BY ATTORNEYS.

United States Patent 3,345,492 SLIDEWIRE CONTACT MECHANISM Gustave Ehrenberg, Havertown, and Frank J. McCulla, Philadelphia, Pa., assignors to Electro-Nite Engineering Co., Philadelphia, Pa., a corporation of Pennsylvania Filed Sept. 28, 1966, Ser. No. 582,639 7 Claims. (Cl. 200-166) This application is a continuation-in-part of application Ser. No. 393,087 filed Aug. 31, 1964, entitled, Linear Induction Motor.

This invention relates to a new and improved slidewire contact mechanism and more particularly relates to a slidewire contact mechanism which is adapted for use with a linear induction motor and a measuring and recording device.

The slidewire contact mechanism disclosed in the prior copending application, referred to hereinabove, has performed highly satisfactorily in use.

It is an object of the present invention to provide an improved slidewire contact mechanism which is extremely durable and which functions with a high degree of reliability.

It is another object of the present invention to provide a slidewire contact mechanism which has increased sensitivity, ease of manufacture, and ease of assembly.

It is another object of the present invention to provide a slidewire contact mechanism which has damping means associated therewith for absorbing vibrations and other similar jolts which might otherwise eifect the contact established between a slidewire and such a contact mechamsm. It is yet another object of the present invention to provide a slidewire contact mechanism which is so arranged that constant line contact is provided between the mechanism and the wires with which the mechanism is in contact.

It is a further object of the present invention to provide a slidewire contact mechanism which is highly reliable in operation and effective in use over prolonged periods of time.

Other objects will appear hereinafter.

The above and other objects of the present invention are accomplished by the provision of a new and unobvious slidewire contact mechanism. The slidewire contact mechanism is connected to an arm which in turn is connected to a supporting block of a moving stator. The arm at its other end may have a pen mounted thereon for recording purposes. The slidewire contact mechanism is utilized to contact U-shaped slidewires of a wire potentiometer. The U-shaped slidewires are supported by guides at one end and will normally have their free ends attached to an insulated connector. The slidewires may be resistance wires having varying ohmic values per linear foot for correlation with different values to be measured. All slidewires of the potentiometer are mounted in a similar manner.

A plurality of contact posts are provided and are connected to the arm which extends from the moving stator. The contact posts extend upwardly from the base of a bracket. The contact posts, may have the appearance of inverted Ys and are biased towards each other to provide constant engagement of such posts with the slidewires. The means for biasing the contact posts together also provides a damping effect and absorbs vibrations while insuring constant contact between such postsand the slidewires. Accordingly, the bracket forms a movable shorting connection between adjacent slidewires and thus the resistance in the potentiometer is being changed as the contact posts move along the slidewires. Suitable insulating means is provided for preventing the bracket from making elec- 3,345,492 Patented Oct. 3, 1967 trical contact with the arm which is attached to the moving stator.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently prefer-red; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a perspective view partially broken away of the slidewire contact mechanism of the present invention;

FIGURE 2 is a perspective view of the bracket which is utilized in the slidewire contact mechanism;

FIGURE 3 is a section view of the slidewire contact mechanism taken along line 3-3 of FIGURE 1;

FIGURE 4 is a section view taken along line 44 of FIGURE 3.

Referring now to the drawings in detail wherein like numerals indicate like structure throughout several views, there is shown in FIGURES 1-4 .a slidewire contact mechanism generally indicated as 10. The mechanism 10 is mounted on an arm 12 which is connected to a moving stator (not shown).

A plurality of aligned pairs of holes 14 are provided on the arm 12. A slidewire contact mechanism 19 is adapted to be mounted in each pair of holes 14 in the manner set forth in FIGURE 1. A pair of bolts 16 are adapted to extend upwardly through the holes 14 in the arm 12. The bolts 14 may be composed of aluminum or any other suitable material or combination of materials. The bolts 14 may be made of non-magnetic or magnetic material are desired. However, in the preferred embodiment aluminum bolts are used. Washers made of nonconducting material are inserted between the bolts 16 and the arm 12. The washer 18 have collars 20 thereon which prevent contact of the bolts 16 with the arm 12. The washers 18 may be composed of polystyrene or any other suitable insulating material.

After passing through the arm 12 the bolts 16 pass through bushings 22 and are received in internally threaded head members 24. The bushings 22 may be made of any suitable insulating material and in the preferred embodiment a polystyrene bushing is utilized. The head members 24 may also be made of any suitable material and in the preferred embodiment the head members are made of aluminum. However, the head members'24 may be made of any magnetic or non-magnetic material as desired. Prior to being received within the head members 24 the bolts pass through a bracket 26. The bracket 26 has slots 28 therein which are adapted to receive the bolts 24. The structure and function of the brackets 26 will be set forth hereinafter in detail.

The head members 24 may have pin members 30 integrally connected thereto. The pin members 30 extend upwardly to a height greater than the uppermost end of the bracket 26. Cylindrical insulators 32 are adapted to fit over the pins 30. The cylindrical insulators 32 may be composed of glass or other suitable material. In the preferred embodiment the insulators 32 are composed of glass. Each of the insulators 32 is provided with an enlarged head 34 at the uppermost end thereof. Each enlarged head 34 has a groove 36 circumscribing the periphery thereof substantially intermediate the ends of the enlarged head 34. A tensioning member 38 is adapted to a uppermost end, the contact posts 42 have outwardly extending flanges 50 integrally connected thereto.

The flanges are substantially the same height as the uppermost end of the enlarged head 34. The tensioning member 38 is adapted to be received immediately be neath the flanges 50 of the contact posts 42 and is adapted to bias said contact posts towards each other. The flanges 50 function to retain the member 38 in engagement with the contact post 42 and prevent inadvertent or accidental separation thereof.

The member 38 will absorb substantially all vibrations and jolts which the mechanism may receive thus permitting providing increased sensibility of the posts 42. The member 38 functions substantially as a damping member and also functions to bias the posts 42 towards each other.

Each of the contact posts 42 may be provided with an indented portion 52 on the body 48 thereof. By indenting a portion of the body 48 of the contact posts 42 a recess 54 is provided on each of the posts 42.

A highly conductive soft metal material 56 may be received within the recess 54 on each of the posts 42. The metal received within the recess 54 may be a gold alloy or other suitable similar material or combination of materials. The metal 56 may be retained within the recess 54 by fusing the metal 56 to the material 54 or by any other suitable means such as welding or the like. In FIG- URE 1 are shown a pair of U-shaped slidewires 58 and 60 which extend around insulated guides 62 and 64 respectively. At their other ends the slidewires 58 and 60 are attached to an insulated connector (not shown). The insulated guides 62 and 64 are shown supported on upwardly extending members 66 and 68 respectively. The structural arrangement of the members 66 and 68 are fully set forth in the copending application referred to hereinbefore.

The slidewires 58 and 6!]! are held under tension by means of their connection to the resilient members 66 and 68 respectively and by means of their connection to an insulated connector at their other ends. The slidewires 58 and 60 may be resistance wires having varying ohmic values per linear foot for correlation with different values to be measured. While only two such slidewires are shown it is obvious that a plurality of such wires may be provided. However, since all slidewires are mounted in a similar manner, for the purpose of the present invention, only slidewires 58 .and 60 have been shown.

The contact posts 42 will contact slidewire legs 58a and 60b of slidewires 58 and 66.

The slidewires 58a and 64b are in constant line contact with the metal 56 which is received in each recess 54 on the contact posts 42 respectively. The resilient tensioning member 38 will prevent vibration or shock from being transmitted to the contact posts 42 and thus insures constant engagement between the metal conductors 56 and the slidewire legs 58a and 6%, which will be resiliently clamped between the contact 56 and glass insulator 32. As arm 12 moves with the moving stator (not shown), the bracket 26 provides a movable shorting connection between the slidewires 58 and 60. Thus, if slidewires 58 and 68 represent potentiometer resistances and wire 60 is shorted at its open end to form a low resistance pick-up bar, the resistance in said potentiometers is being changed as the bracket 26 connects slidewires 58 and 60 together at different positions therealong.

The slidewire 58 is preferably made from a commercially available alloy having a high resistance such as 1525 ohms per foot. Slidewire 6i) may be made of the same alloy but of larger diameter to give relatively low resistance.

In operation, the bracket 26 insures that constant movable shorting connection is established and maintained between the slidewires 58 and 60. The bracket 26 is completely insulated from the arm 12 since it is mounted on insulator bushings 22 and the bolts 16. The resilient tensioning member 38 functions as a damping means and also insures that the contact posts 42 will be biased towards each other and therefore against slidewires 58 and 60. Utilization of the slidewire contact mechanism 10 insures trouble-free superior operation of the linear induction motor (not shown) with which the mechanism cooperates.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

We claim:

l. A slidewire contact mechanism adapted to contact slidewires comprising a support arm, a bracket mounted on and electrically isolated from said arm, said bracket having a pair of contact means electrically coupled and extending upwardly therefrom, said contact means being adapted to be in engagement with slidewires, a resilient means electircally isolated from said support arm engaging each of said contact means wherein said resilient means dampens vibrations thus substantially preventing the transmission of vibrations to said contact means.

2. A slidewire contact mechanism as set forth in claim ll wherein said resilient means includes column means electrically isolated from said arm positioned in a plane between the planes of said contact means and an elastomeric member extending around said column means and resiliently engaging each of said contact means, said elastomeric material biasing said contact means towards said column means to thereby resiliently clamp a slidewire between said column means and said contact means.

3. A slidewire contact mechanism as set forth in claim 1 wherein said pair of contact means includes two spacedapart members each having at least one leg and a body, a portion of said body of each of said contact means being indented to provide a recess and a highly conductive material received within said recess to provide line contact with slidewires.

4. A slidewire contact mechanism as set forth in claim 2 wherein said column means includes spaced substantially cylindircal shaped members, aligned grooves in each of said members, said elastomeric member being received within said grooves.

5. A slidewire contact mechanism as set forth in claim 4, wherein said pair of contact means includes a plurality of spaced members, each of said members having an outwardly depending flange at its end, said elastomeric member adapted to engage said spaced members immediately adjacent said flanges, said flanges preventing accidental or inadvertent removal of said elastomeric member during use of the slidewire contact mechanism.

6. A slidewire Contact mechanism as set forth in claim 3 wherein saidresilient means includes a pair of substantially cylindrical columns electrically isolated from said arm, the vertical plane defined by said columns being substantially perpendicular to the vertical plane defined by said spaced-apart members.

7. A slidewire contact mechanism as set forth in claim 6 wherein said cylindrical columns have enlarged upper ends, a groove in each of said enlarged upper ends, and an elastomeric member within said grooves.

No references cited.

ROBERT K. SCI-IAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner. 

1. A SLIDEWIRE CONTACT MECHANISM ADAPTED TO CONTACT SLIDERWIRES COMPRISING A SUPPORT ARM, A BRACKET MOUNTED ON AND ELECTRICALLY ISOLATED FROM SAID ARM, SAID BRACKET HAVING A PAIR OF CONTACT MEANS ELECTRICALLY COUPLED AND EXTENDING UPWARDLY THEREFROM, SAID CONTACT MEANS BEING ADAPTED TO BE IN ENGAGEMENT WITH SLIDEWIRES, A RESILIENT MEANS ELECTRICALLY ISOLATED FROM SAID SUPPORT ARM ENGAGING EACH OF SAID CONTACT MEANS WHEREIN SAID RESILIENT MEANS DAMPENS VIBRATIONS THUS SUBSTANTIALLY PREVENTING THE TRANSMISSION OF VIBRATIONS TO SAID CONTACT MEANS. 